semi aero 700c rims

[andy]

Been following the thread on rims and was wondering what everyone's thoughts
are on semi-aero rims such as mavic cxp33 and velocity aeroheads. Any real
aero advantages? What about the aerohead(19.5mm) vs. cxp33(23.5mm)
sidewalls? The aeroheads are much cheaper and lighter too. Thanx in advance.
andy

[Marty Wallace]

"andy" <trifox13atcovaddotnet> wrote in message
ervers.com...
> Been following the thread on rims and was wondering what everyone's
thoughts
> are on semi-aero rims such as mavic cxp33 and velocity aeroheads. Any real
> aero advantages? What about the aerohead(19.5mm) vs. cxp33(23.5mm)
> sidewalls? The aeroheads are much cheaper and lighter too. Thanx in
advance.
> andy
>
>
I recently bought some Aeroheads and I really like them. I like the offset
rim for the rear. I have Conti tyres on and it's a great combo.

Marty

[Alex Rodriguez]

In article s.com>,
trifox13atcovaddotnet says...
>Been following the thread on rims and was wondering what everyone's thoughts
>are on semi-aero rims such as mavic cxp33 and velocity aeroheads. Any real
>aero advantages? What about the aerohead(19.5mm) vs. cxp33(23.5mm)
>sidewalls? The aeroheads are much cheaper and lighter too. Thanx in advance.

No real aero advantages unless you use less spokes.
--------------
Alex

[daveornee]

Andy wrote:
> Been following the thread on rims and was wondering what everyone's
> thoughts are on semi-aero rims such as mavic cxp33 and velocity
> aeroheads. Any real aero advantages? What about the aerohead(19.5mm) vs.
> cxp33(23.5mm) sidewalls? The aeroheads are much cheaper and lighter too.
> Thanx in advance. andy



No significant aero advantages either way. CXP33 is slightly heavier due
to the small nipple cradling castings that are held by the spoke holes
with the "spring material" that is between the inner and outer rim
walls. I have built both. CXP33 is slightly easier to build because you
can just drop the nipples in the spoke holes, but the OCR version of the
Aerohead gives it a durability edge for rear wheels. You can also get
Velocity Aerohead rims without machining on the brake surface. My
experience is limited to a couple of samples, but I like the option of
not having any material removed by a machine that will effect the life
of the rim in use. If you want aero advantages, use Velocity Deep V,
fewer spokes, and get wind tunnel tested for aero riding position.



--

[dvt]

daveornee wrote:
> CXP33 is slightly easier to build because you
> can just drop the nipples in the spoke holes...

That's a nice feature. The Aerohead has no eyelets or ferrules, and the
nipple is easily lost in the rim. Of course, it's pretty easy to get
out, but it's a bit of a pain in the butt.

> ...but the OCR version of the
> Aerohead gives it a durability edge for rear wheels.

I build an Aerohead OCR rear wheel a few weeks back. That offset spoke
bed makes the rear wheel much easier to build. I can't give an opinion
on durability since I haven't ridden them for very long.

> You can also get
> Velocity Aerohead rims without machining on the brake surface. My
> experience is limited to a couple of samples, but I like the option of
> not having any material removed by a machine that will effect the life
> of the rim in use.

Yes, you can get the Aerohead without machined sides. And you can get
them powdercoated instead of anodized. But you can't get them with both
of these features. That is, the powdercoated walls all have machined
sidewalls. Or so I was told. I guess it makes some sense, since I don't
think the brakes would work very well as long as the powdercoating was
still on the sides.

They also don't have welded joints. I like that because it should be
cheaper and I don't see the advantage of welding. The powdercoated
versions come in red, yellow or blue. I don't like that, since I like to
keep the rims pretty low-key so they can be used on different bikes.

--
Dave, who has yellow rims
dvt at psu dot edu